Hydraulic valves with plastic housings are known. The housing can be made by injection molding, which permits the production of large numbers at a high accuracy. However, securing two plastic parts of the housing together to withstand forces is a challenge.
Water meters are also known with plastic housings. The trend with water meters is towards the use of plastic meters, as opposed to metal meters. One reason for this trend is that many jurisdictions now require zero lead content in the water supply and accordingly, meters in contact with the water supply also need to have zero lead content. Plastic meters satisfy this zero lead content requirement.
U.S. Pat. No. 8,353,208 describes a water meter having a two-part plastic housing. The housing has an upper housing part and lower housing part, which are connected with a plurality of comb-like retaining columns. The retaining columns at the upper housing part or lower housing part are shaped complementary to one another and mate together so that the housing parts can be plugged together. The retaining columns are oriented in the direction in which the tensile force between the upper housing part and lower housing part is directed, when the housing is subjected to internal pressure. Retaining grooves, which are oriented transverse to the effective direction of the tensile force, are formed in two opposite surfaces of the retaining columns. Retaining bolts, which at least partially touch the surfaces formed by the retaining grooves, can be inserted in the retaining grooves. The comb-shaped retaining columns are subjected only to tension and not to bending. The retaining bolts are subjected only to shearing.